Free online IGES (.iges/.igs) converter. Convert IGES CAD files to STL, GLB, glTF, OBJ, PLY in your browser — no upload, no watermark.
.iges or .igs file, or click "Choose 3D file". The two extensions are the same format, so either works. Your CAD file is read directly in the page using a WebAssembly build of the OpenCASCADE geometry kernel — the engine loads once, then conversions are near-instant.IGES (Initial Graphics Exchange Specification, officially Digital Representation for Communication of Product Definition Data) was first published in March 1980 by the U.S. National Bureau of Standards — now NIST — as a neutral way to move CAD data between otherwise incompatible systems. Its last version, IGES 5.3, was finalized as an ANSI standard in 1996, and active development effectively stopped after STEP (ISO 10303) arrived in 1994. For new CAD interchange, STEP has largely superseded it, but decades of legacy parts, vendor exports, and archived designs still ship as .iges and .igs.
The important thing to understand is what an IGES file holds. It is a B-rep and surface format: it describes exact mathematical curves, trimmed surfaces, and solids — not triangles. That is the opposite of a mesh format. So almost everything downstream of CAD — slicers, game engines, AR viewers, web pages, scan tools — cannot read IGES directly and needs a triangle mesh instead. Converting bridges that gap by tessellating the precise surfaces into a mesh the destination can actually open:
.glb loads cleanly in <model-viewer>, WebXR, Three.js, Unity, and Unreal.One thing this tool deliberately does not do is the reverse. There is no mesh-to-IGES export here — turning a triangle mesh back into clean B-rep surfaces is a hard reverse-engineering problem, not a file conversion, so this hub is one-way: IGES in, mesh out.
| Format | Type | Geometry stored | Materials / color | Best for |
|---|---|---|---|---|
| IGES (.iges / .igs) | B-rep + surfaces + wireframe (text) | Exact curves & surfaces | No | Legacy CAD interchange |
| STL (.stl) | Triangle mesh | Tessellated triangles only | None | 3D printing / slicers |
| 3MF (.3mf) | Zipped XML print package | Tessellated triangles | Color + units | Modern color 3D printing |
| GLB / glTF | Binary / JSON runtime scene | Tessellated triangles | PBR materials + textures | Web, AR, game engines |
| OBJ (.obj) | Text mesh (often + .mtl) | Tessellated triangles | External .mtl materials |
Broad modeling-app support |
| PLY (.ply) | Polygon mesh | Tessellated triangles | Per-vertex color | 3D scans, point clouds, research |
Not here, and generally not by simple conversion. IGES stores exact B-rep surfaces and curves, while STL, OBJ, GLB, and PLY store flat triangles. Going from a triangle mesh back to clean parametric CAD surfaces is a reverse-engineering task — fitting surfaces to the mesh — and tools that attempt it (like Fusion 360's Mesh-to-BRep or dedicated reverse-engineering software) approximate the result rather than recover the original geometry. This converter is one-way by design: it reads IGES and writes a mesh, never the other direction.
Some, and that is unavoidable. Tessellation replaces IGES's exact curved surfaces with a finite number of flat triangles, so a perfectly round hole becomes a many-sided polygon. The denser the tessellation, the closer the mesh hugs the true surface and the larger the file. For 3D printing this is fine — the slicer works in triangles anyway and the printer's resolution is the real limit. For dimensional inspection or further CAD editing, you want to keep the original IGES (or better, a STEP file), because the mesh is an approximation of the geometry, not the geometry itself.
Both give you a printable mesh; they differ in what rides along. STL is geometry only and is read by essentially every slicer, which makes it the safe default for a single-material print. 3MF, an XML-and-ZIP package from the 3MF Consortium (2015), can also store color, multiple materials, units, and print metadata in one file, so it is the better choice for color or multi-material prints on slicers and printers that support it.
For anything new, prefer STEP (ISO 10303). STEP is the modern neutral CAD format: it reliably preserves solid B-rep geometry, assemblies, and metadata, and every current CAD system reads and writes it. IGES dates to 1980 and its last revision, 5.3, is from 1996; it more often stores loose surfaces that can have gaps or missing faces. You will still receive IGES from older systems and archives, which is exactly when converting it to a usable mesh — or asking the sender for a STEP file — makes sense.
Because those tools speak triangles, and IGES does not contain any. A slicer, Blender, Unity, or a web <model-viewer> all expect a tessellated mesh; IGES holds exact surfaces and curves that have to be converted into triangles first. Uploading the .iges here and exporting STL, OBJ, or GLB produces the mesh those programs can actually load.
No. IGES conversion on this page runs entirely in your browser using a WebAssembly build of the OpenCASCADE geometry kernel — your file is read, tessellated, and downloaded on your own device, so the model never leaves your computer. That matters for proprietary or unreleased parts: there is no upload, no account, and no watermark. In our testing, a small IGES bracket exported to GLB after the engine finished loading, producing a single binary mesh from the source surfaces with no network upload.